/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jdbc.support.lob;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.transaction.TransactionSystemException;
import org.springframework.transaction.support.TransactionSynchronizationManager;

import javax.transaction.Status;
import javax.transaction.TransactionManager;

/**
 * Helper class for registering a transaction synchronization for closing
 * a LobCreator, preferring Spring transaction synchronization and falling
 * back to plain JTA transaction synchronization.
 *
 * @author Juergen Hoeller
 * @see SpringLobCreatorSynchronization
 * @see org.springframework.transaction.support.TransactionSynchronizationManager
 * @see JtaLobCreatorSynchronization
 * @see javax.transaction.Transaction#registerSynchronization
 * @since 2.0
 */
public abstract class LobCreatorUtils {

    private static final Log logger = LogFactory.getLog(LobCreatorUtils.class);


    /**
     * Register a transaction synchronization for closing the given LobCreator,
     * preferring Spring transaction synchronization and falling back to
     * plain JTA transaction synchronization.
     *
     * @param lobCreator            the LobCreator to close after transaction completion
     * @param jtaTransactionManager the JTA TransactionManager to fall back to
     *                              when no Spring transaction synchronization is active (may be {@code null})
     * @throws IllegalStateException if there is neither active Spring transaction
     *                               synchronization nor active JTA transaction synchronization
     */
    public static void registerTransactionSynchronization(
            LobCreator lobCreator, TransactionManager jtaTransactionManager) throws IllegalStateException {

        if (TransactionSynchronizationManager.isSynchronizationActive()) {
            logger.debug("Registering Spring transaction synchronization for LobCreator");
            TransactionSynchronizationManager.registerSynchronization(
                    new SpringLobCreatorSynchronization(lobCreator));
        } else {
            if (jtaTransactionManager != null) {
                try {
                    int jtaStatus = jtaTransactionManager.getStatus();
                    if (jtaStatus == Status.STATUS_ACTIVE || jtaStatus == Status.STATUS_MARKED_ROLLBACK) {
                        logger.debug("Registering JTA transaction synchronization for LobCreator");
                        jtaTransactionManager.getTransaction().registerSynchronization(
                                new JtaLobCreatorSynchronization(lobCreator));
                        return;
                    }
                } catch (Throwable ex) {
                    throw new TransactionSystemException(
                            "Could not register synchronization with JTA TransactionManager", ex);
                }
            }
            throw new IllegalStateException("Active Spring transaction synchronization or active " +
                    "JTA transaction with specified [javax.transaction.TransactionManager] required");
        }
    }

}
